Flaviviruses are a group of human pathogenic, enveloped RNA viruses that includes dengue (DENV), yellow fever (YFV), West Nile (WNV), and Japanese encephalitis (JEV) viruses. Cross-reactive antibodies against Flavivirus have been described, but most of them are generally weakly neutralizing. In this study, a novel monoclonal antibody, designated mAb 2A10G6, was determined to have broad cross-reactivity with DENV 1–4, YFV, WNV, JEV, and TBEV. Phage-display biopanning and structure modeling mapped 2A10G6 to a new epitope within the highly conserved flavivirus fusion loop peptide, the 98DRXW101 motif. Moreover, in vitro and in vivo experiments demonstrated that 2A10G6 potently neutralizes DENV 1–4, YFV, and WNV and confers protection from lethal challenge with DENV 1–4 and WNV in murine model. Furthermore, functional studies revealed that 2A10G6 blocks infection at a step after viral attachment. These results define a novel broadly flavivirus cross-reactive mAb with highly neutralizing activity that can be further developed as a therapeutic agent against severe flavivirus infections in humans.
In intestinal epithelial cells, inactivation of APC, a key regulator of the Wnt pathway, activates beta-catenin to initiate tumorigenesis. However, other alterations may be involved in intestinal tumorigenesis. Here we found that RUNX3, a gastric tumor suppressor, forms a ternary complex with beta-catenin/TCF4 and attenuates Wnt signaling activity. A significant fraction of human sporadic colorectal adenomas and Runx3(+/-) mouse intestinal adenomas showed inactivation of RUNX3 without apparent beta-catenin accumulation, indicating that RUNX3 inactivation independently induces intestinal adenomas. In human colon cancers, RUNX3 is frequently inactivated with concomitant beta-catenin accumulation, suggesting that adenomas induced by inactivation of RUNX3 may progress to malignancy. Taken together, these data demonstrate that RUNX3 functions as a tumor suppressor by attenuating Wnt signaling.
The transcription factor RUNX3 functions as a tumor suppressor in the gastrointestinal epithelium, where its loss is an early event in carcinogenesis. While RUNX3 acts concurrently as a mediator of TGF-b signaling and an antagonist of Wnt, the cellular changes that follow its loss and their contribution to tumorigenicity are not fully understood. Here, we report that the loss of Runx3 in gastric epithelial cells results in spontaneous epithelial-mesenchymal transition (EMT). This produces a tumorigenic stem cell-like subpopulation, which remarkably expresses the gastric stem cell marker Lgr5. This phenomenon is due to the compounding effects of the dysregulation of the TGF-b and Wnt pathways. Specifically, Runx32/2 gastric epithelial cells were unexpectedly sensitized for TGF-binduced EMT, during which the resultant induction of Lgr5 was enhanced by an aberrantly activated Wnt pathway. These data demonstrate a protective role for RUNX3 in safeguarding gastric epithelial cells against aberrant growth factor signaling and the resultant cellular plasticity and stemness.
Reactive oxygen species (ROS) and cellular oxidant stress have long been associated with cancer. Here, we show that TIP30, also called CC3, regulates p53 mRNA stability and induces apoptosis by sensing of intracellular oxidative stress in human hepatocellular carcinoma (HCC) cells. Introduction of TIP30 induced more cell death in HepG2 cells with a high level of intracellular ROS than that in normal liver cell line, HL7702, which had low level of intracellular ROS. Treatment with an antioxidant agent attenuated TIP30-induced cell death in HepG2 cells, whereas oxidant H 2 O 2 augmented TIP30-induced cell death in HL7702 cells. The conformation of TIP30 was altered with the formation of an intermolecular disulfide bridge under oxidative stress. TIP30 greatly enhanced p53 expression and its transcriptional activity under oxidative stress, which was probably through stabilization of p53 mRNA. TIP30 induced apoptosis and mitochondrial dysfunction were blocked by silencing of p53 expression. The nuclear import of mRNA-binding protein HuR was blocked upon TIP30 introduction, which might be due to the interruption of the association of HuR with importin B2. The elevated cytoplasmic HuR bound to p53 mRNA 3 ¶-untranslated region, resulting in prolonged half-life of p53 mRNA. Our results suggest that TIP30 is involved in cellular oxidative stress surveillance and induces apoptosis through stabilization of p53 mRNA in HCC cells. [Cancer Res 2008;68(11):4133-41]
Smart windows with adjustable transmittance via physical stimuli are eagerly desired for sorts of energy‐saving lighting systems. However, reciprocal trade‐off relationship such as high transparency and coloration/discoloration ability exists in smart windows, not conducive to optical‐electrical coupling and leap in performance. Substituting for common composites utilized in smart windows, here, single transparent ceramic‐based smart windows are reported through composition design and defect management strategies to regulate the optoelectronic performances and break off the contradictions between optical transmittance, photo‐thermochromism and electrical conductivity. By first principles calculations and precisely tuning Er3+, Ba2+, Sr2+ concentrations in non‐stoichiometric Er‐doped (K0.5Na0.5)NbO3‐(Ba, Sr)TiO3, the fabricated ceramics exhibit brilliant transparency and multi‐mode dramatical and reversible modulations of pellucidity, photoluminescence intensity, along with conductivity (over fivefold variation), enabling prominent optoelectronic information storage and modulating capacity in vivid potential applications, such as easy‐readout/erasable optical memorizers, photo‐memristors and anti‐counterfeiting displays.
Multi-mode modulations of near-infrared and visible optical behaviors in xNd-KNN translucent ceramics are induced by color center-related photochromism reactions.
Tumor metastasis leads to high mortality; therefore, understanding the mechanisms that underlie tumor metastasis is crucial. Generally seen as a secretory protein, osteopontin (OPN) is involved in multifarious pathophysiological events. Here, we present a novel pro-metastatic role of OPN during metastatic colonization. Unlike secretory OPN (sOPN), which triggers the epithelial–mesenchymal transition (EMT) to initiate cancer metastasis, intracellular/nuclear OPN (iOPN) induces the mesenchymal–epithelial transition (MET) to facilitate the formation of metastases. Nuclear OPN is found to interact with HIF2α and impact the subsequent AKT1/miR-429/ZEB cascade. In vivo assays confirm that the progression of metastatic colonization is accompanied by the nuclear accumulation of OPN and the MET process. Furthermore, evidence of nuclear OPN in the lung metastases is exhibited in clinical specimens. Finally, VEGF in the microenvironment was shown to induce the translocation of OPN into the nucleus through a KDR/PLCγ/PKC-dependent pathway. Taken together, our results describe the pleiotropic roles of OPN in the tumor metastasis cascade, which indicate its potential as an effective target for both early and advanced tumors.
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